By Dave Andrusko

"Patients in vegetative or minimally conscious states may not be able to speak for themselves or report that they are aware of their surroundings, but some can learn, according to a new study," read the first sentence of one news account. "The researchers say that they believe that the fact that these patients can learn also reveals that they can form memories and that they may benefit from rehabilitation," read another.

In a word, Wow!

Like many of you, I have long suspected that not only are patients with severe cognitive impairment often misdiagnosed, they also have a much richer interior life than the "experts" insist. And every year or two a study, like this collaboration between the University of Buenos Aires and the Institute of Cognitive Neurology, both in Argentina, and the University of Cambridge, proves us right.

This is really interesting, so if I go a little geekish on you, bear with me.

How is on to figure out if people with various "disorders of consciousness" [DOC] can learn? DOC is awfully inclusive but for our purposes it includes people who are diagnosed as being in a so-called "persistent vegetative state" (PVS) or who are said to be in a "minimally conscious state."

Like all good science, the researchers had control groups.

Dr. Tristan Bekinschtein

The study participants were divided into three groups –"16 healthy individuals, and 22 vegetative or partially conscious patients, and 12 subjects given general anesthesia." The study leader, Dr. Tristan Bekinschtein from the University of Cambridge, "measured activity in subjects' eye muscles in the half-second between playing the tone and spraying the air puff to test their response," according to Victoria Stern.

"As expected, the healthy patients showed extensive eye muscle movement in the interval between the tone and the air puff, while the anesthetized patients showed no notable eye muscle activity between the two stimuli," she wrote. "Surprisingly, however, 15 of the vegetative, minimally conscious and severely impaired patients showed a significant spike in muscle activity after the hearing the tone, indicating at least some degree of learning."

Why are the results from the anesthetized patients important? Because it is "suggesting that the learning does not happen when [someone is] truly unconscious, and that some patients may have some level of consciousness not apparent on traditional tests."

Put another way, the DOC patients "were clearly anticipating the stimulus would come, so there is some kind of perception and from the point of view of the patient who is allegedly unconscious this could have profound implications," Dr Bekinschtein told BBC News.

Two other quick points. "Interestingly, the researchers did not find any difference in learning between those in a vegetative state and those in a minimally conscious state. 'What [this] tells us is that there might be a fair amount of misdiagnosis, or that some of the vegetative subjects were in fact minimally conscious,'" Bekinschtein told LiveScience.

Second, "Determining cognitive processing capacity in behaviorally unresponsive patients has been a real dilemma for clinicians working in brain injury," Joseph Giacino, the associate director of neuropsychology at the JFK Medical Center in Edison, NJ, who was not involved in the research, told Stern. "This study provides strong evidence of an active, selective learning process in these patients."

There is another fascinating study that we discussed last April in NRL News. "In a small, unique experiment carried out by research physicians from Cornell and Columbia universities in New York and Georgetown University in Washington, two brain-injured patients showed remarkable evidence of a potential ability to hear and understand the voices of close family members, with a brain response indistinguishable from that of a normal, alert person."

It is attached as Part Three.

Please send your comments to daveandrusko@gmail.com

Part Three
Part One